The invention relates to a conveyor system, including a conveyor course, which has at least one curved portion with an axis of curvature and a radius of curvature, in which a conveying direction or longitudinal direction pointing along the conveyor course, a upright direction extending parallel to the axis of curvature, and a crosswise direction extending orthogonally to both the conveying direction and the upright direction, may be associated with this conveyor course, and in which the conveyor course moreover has two tracks, one above the other in the upright direction and extending at a predetermined spacing from one another; and furthermore including a conveyor carriage having at least three rollers, in which at least one track roller having an axis of rotation extending substantially in the upright direction is assigned to each of the tracks, and in which at least one of the tracks is assigned a further track roller with an axis of rotation extending substantially in the upright direction, which axis is spaced apart in the conveying direction from the one track roller associated with the same track.
Already at this point, the term “upright direction”, but also the other orientation indications maintain their validity even if the conveyor course extends at a predetermined angle to the horizontal. In that case, the “upright direction” will also not run exactly in the direction of the vertical but rather will form the predetermined angle with it. It should also be remembered that the conveying direction, in curved portions of the conveyor course, extends in the direction of the tangent to the particular place on the conveyor course in question.
A generic conveyor system is known for instance from U.S. Pat. Nos. 5,960,938, 6,062,378, and 6,237,755 B1. The known conveyor system includes a conveyor course, embodied as a profile girder, with a first roller track, whose surface is inclined to the horizontal by a slight angle, so that it can absorb the support load of the conveyor carriage that is transmitted from support rollers. Moreover, two further roller tracks are provided, of which one extends substantially vertically and the other forms a slight angle with the vertical. Via these two roller tracks, track rollers transmit the torque, exerted by a load applied to the conveyor carriage laterally, to the conveyor course. The two further roller tracks are spaced apart from one another not only in the upright direction of the conveyor course but also in the crosswise direction. Overall, the conveyor carriage has two such roller triplets, which are spaced apart from one another in the longitudinal direction of the conveyor course.
In practice, it has been found that the conveyor carriage of this known conveyor experience problems when traveling through curved portions of the conveyor course, and especially when cornering. Specifically, these problems increase all the more, the greater the curvature of the curved portion of the course, that is, the tighter the curve. As will readily be appreciated, it is precisely the tightest possible curve radius that is definitive for how much installation space must be made available for a conveyor system.
Solely for the sake of completeness, U.S. Pat. Nos. 3,646,656 and 4,331,229 may be mentioned.